In a case where a moving video picture is captured by an image sensor capable of capturing a still image of high pixel density, the readout speed of the sensor is not high enough so that a low frame rate results. Methods for binning pixel signals and methods for interlacing pixel signals are known as methods for achieving high frame rate.
Binning of the pixel signals is accomplished by adding up signals of plural adjacent pixels of the image sensor, such as signals of a total of 4 pixels including 2 horizontal pixels and 2 vertical pixels. Such binning of the pixel signals involves resolution deterioration. In this connection, Japanese Unexamined Patent Publication No. 2002-57943 discloses a technique wherein a binning phase is inverted on a row-by-row basis in binning horizontal/vertical pixel signals. This prior-art technique falls short of preventing the resolution deterioration although the deterioration of horizontal resolution can be reduced.